Combination geometrical instrument



M. W. CRANE.

COMBINATION GEOMETRICAL INSTRUMENT.

APPLICATION FILED MAY 14, 1918.

1,337,823; Patented p 20,1920,

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Guam,-

M, W. CRANE.

COMBINATION GEOMETRICAL INSTRUMENT.

APPLICATION FILED MAY14, 1918.

1,337,823 Patented Apr. 20, 1920.

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or MoLINn, ILLINOIS.

COMBINATION GEOMETRICAL INSTRUMENT.

Application filed To all whom it may concern:

Be it known that I, MnLvILLn IV. CRANE, a citizen of the United States, residing at Moline, in the county of Rock Island and State of Illinois, have invented certain new and useful Improvements in Combination Geometrical Instruments, of which the following is a specification.

This invention relates to improvements in geometrical instruments and it is the principal object of the invention to provide a combination geometrical tool for use in die and pattern making, whereby die bushings and patterns varying in shape can be accurately and easily laid out by a user without any loss of time.

Other independent objects are to provide features of construction of portions of the tool which tend toward the attainment of the above aims irrespective of the relation in which they are used.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the following claim.

In the accompanying drawings wherein I have shown one of various possible embodiments of my invention:

Figure 1 is a front elevation of the improved tool,

Fig. 2 is a vertical transverse section therethrough,

Fig. 3 is a detail in elevation of the hinge connection of one of the protractor blades,

Fig. 4; is a horizontal section through the tool showing the manner in which the ad justable blade is engaged with the tool head, and

Fig. 5 is a detail in section taken on the line 5-5 of Fig. 1.

Having more particular reference to the drawings, in connection with which like reference characters will designate corresponding parts throughout the several views, 1 represents the center head or square of the improved tool, the extremities of which, as shown in Fig. 2 are formed of angle metal, while the main portion thereof is Specification of Letters Patent.

lt-Eay 14-, 1918.

Patented Apr. 20, 1920.

Serial Ho. 234,409.

provided with a longitudinally disposed wayhaving a screw threaded opening communicating therewith whereby an adjusting blade 2 can be slidably mounted thereon.

The adjusting blade 2 is formed with a longitudinally disposed slot 3, while one side thereof is provided with aseries of graduations designated by the numeral 4. A thumb screw 5 is passed through the longitudinally disposed slot in the adjusting blade 2 into engagement with the screw threaded opening formed in the head 1 and, obviously, serves to lock the blade in the various positions to which it may be adjusted; a washer 6 being interposed between the head of the thumb screw and the blade to insure proper functioning thereof.

Protractor blades 7 and 8 are provided, the adjacent ends thereof being enlarged as at 9 and apertured in order that the same may be pivotally connected to the apertured end 10 of the adjusting blade 2, a bolt 11 passing through the adjacent parts and having a suitable form of thumb nut 12 turned into engagement therewith whereby said part can be locked in adjusted positions. Certain of the sides of the protractor blades are of course graduated as indicated by the numeral 18, while portions of the sides of the enlarged ends 9 thereof are also graduated as at 14, thus facilitating the laying out of various figures.

In using the improved tool, the center head is placed against the side of a die bushing or like work whereupon the adjusting blade and protractor blades are properly adjusted whereupon the work can be laid out from the center of the bushing by the use of the protractor blades. Obviously, the adjusting blade 2 and protractor blades 7 and 8 can be moved to various positions and locked therein against undue movement, such as conditions or preference may dietate. In this way, it will be readily understood by persons skilled in the art, that the tool can be advantageously used for accurately and quickly laying out various forms of work, such for instance, as square, hexagon, octagon and other irregular shaped die bushings, such as used in the die making art.

Manifestly, the construction shown is capaole of considerable modification and such modification as is within the scope of my claim, I consider Within the spirit of my invention.

I claim:

The combination with a center head, of an adjustable blade having a medial longitudinal slot, means for adjustably securing the blade on the angle and Working in the slot, and protractor arms pivotally connected to the blade at the end adjacent to the angle.

In testimony whereof I afliX my signature hereto.

' MELVILLE vW. CRANE. 

